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Stephen Day

Gas Safe Engineer at iHeat

Stephen Day is a Gas Safe registered and FGAS certified engineer with over 20 years of hands-on experience in the heating, cooling, and renewable energy industry, specialising in boiler installations, air conditioning, and heat pump systems.

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About Stephen Day

Stephen Day is a Gas Safe registered and FGAS certified engineer with over 20 years of hands-on experience in the heating, cooling and renewable energy industry.

Throughout his career, Stephen has designed, installed and maintained thousands of systems across homes and businesses in the UK. His background on the tools, combined with his directorship role at iHeat, gives him a rare understanding of both the technical and operational sides of the industry.

He has helped to secure Which? Trusted Trader accreditation all with a focus on delivering great service and long-term value for customers. He also writes for the iHeat blog, sharing practical advice and explaining heating topics in plain, helpful language.

Stephen continues to stay up to date with the latest heating technologies, building regulations and low-carbon innovations.

Gas Safe ID: 5910722

Expertise

  • Boiler systems and installation
  • Heat pumps and hybrid heating systems
  • Gas safety and compliance
  • System design
  • Renewable and low-carbon technologies
  • Technical training


Articles by Stephen Day are reviewed by iHeat’s technical team for accuracy and reliability.

Stephen Day's latest articles

Worcester Bosch Vs Viessmann Boilers

05th February, 2026 Comparisons

Worcester Bosch Vs Viessmann B...

Which boiler will come out the winner between these two powerhouse boiler manufactures!

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Worcester Bosch Greenstar CDi Compact Combi Review

05th February, 2026 Reviews

Worcester Bosch Greenstar CDi...

One of the most popular compact combi boilers on the market, here we take an in depth look...

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Worcester Bosch Greenstar 2000 Boiler Review

05th February, 2026 Reviews

Worcester Bosch Greenstar 2000...

Worcester Bosch has a new range of condensing combi boilers, including the Worcester Bosch...

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What Type of Boiler Is Right for Me?

05th February, 2026 Guides

What Type of Boiler Is Right f...

Our guide explores the different types of boilers available, including combi, system, and...

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What is Boiler Modulation?

05th February, 2026 Guides

What is Boiler Modulation?

A modulating boiler not only adjusts its output to meet the varying heat demands of your h...

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What is a Boiler PCB?

05th February, 2026 Guides

What is a Boiler PCB?

Our helpful PCB blog provides a comprehensive explanation of the Printed Circuit Board (PC...

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What is a Boiler Filling Loop? In-Depth UK Guide

05th February, 2026 Advice

What is a Boiler Filling Loop?...

When it comes to Boilers, there can be some confusing jargon. Just what exactly is a Boile...

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Vokera Boiler Red Light

05th February, 2026 Guides

Vokera Boiler Red Light

When a Vokera boiler presents a red light, it often indicates a lockout due to safety mech...

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Vokera Boiler Error Codes - How To Fix

05th February, 2026 Guides

Vokera Boiler Error Codes - Ho...

Familiarising yourself with common Vokera fault codes and their meanings can be crucial in...

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Vaillant F62 Fault Code

05th February, 2026 Guides

Vaillant F62 Fault Code

Error codes on boilers can be a confusing and frustrating topic, here at iHeat we want to...

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Vaillant F49 Boiler Error Code - How To Fix

05th February, 2026 Guides

Vaillant F49 Boiler Error Code...

The Vaillant F49 error code is a specific fault indicator on Vaillant boilers, signifying...

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Vaillant Boilers Reviews

04th February, 2026 Reviews

Vaillant Boilers Reviews

Vaillant offers an extensive selection of boilers to cater to different household requirem...

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